Abstract: The Water Diversion Project from the Three Gorges Reservoir to the Hanjiang River (WDTGH) is the follow-up project of the Middle Route Project (MRP) of South-to-North Water Diversion (SNWD). The determination of water diversion quantity involves the water source area of the Three Gorges Reservoir, the Hanjiang River basin and the water receiving area of the middle route project. and is characterized by wide range of analysis, many influential factors and complex boundary conditions, etc. Based on the prediction on water demand in the water receiving area of MRP in 2030, this paper constructs a water resources joint regulation model of the Three Gorges Reservoir, Danjiangkou Reservoir and the MRP, and determines the water diversion quantity of the diversion project by combined regulation calculation of long series of water resources data. Furthermore, the effects of various diversion schemes are preliminarily analyzed. The method and ideas can provide references for the scale demonstration of WDTGH and other water diversion projects.